Unidirectional winder
A winder for a blind system, comprising a drive member rotatable in a drive direction and a free direction; a driven member to engage a blind cylinder; a transmission mechanism to selectively transmit rotation of the drive member to the driven member, the transmission mechanism including an intermediate transmission member and an intermediate resistor to provide resistance to rotation of the intermediate transmission member, wherein the transmission mechanism has a drive state when the drive member is rotated in the drive direction to overcome the resistance of the intermediate resistor and transmit rotation of the drive member through the intermediate transmission member to the driven member, and a free state when the drive member is rotated in the free direction, wherein transmission is broken between the drive member and the intermediate transmission member and intermediate resistor.
1. A winder for a blind system, comprising:
a drive member rotatable in a drive direction and a free direction;
a driven member to engage a blind cylinder;
a transmission mechanism to selectively transmit rotation of the drive member to the driven member, the transmission mechanism including a cam member, an intermediate transmission member and an intermediate resistor to provide resistance to rotation of the intermediate transmission member,
wherein the transmission mechanism has:
a drive state when the drive member is rotated in the drive direction to overcome the resistance of the intermediate resistor and transmit rotation of the drive member through the intermediate transmission member to the driven member, and
a free state when the drive member is rotated in the free direction, wherein transmission is broken between the drive member and the intermediate transmission member and between the drive member and the intermediate resistor.
2. A winder according to claim 1 , wherein the cam member selectively creates a first disengagement point between the drive member and the intermediate transmission member when the drive member is rotated in the free direction, and closes the first disengagement point when the drive member is rotated in the drive direction.
3. A winder according to claim 2 , wherein one of the drive member and the cam member comprises a boss, and the other of the drive member and the cam member comprises a drive cam surface to engage the boss upon rotation of the drive member in the drive direction, to move the transmission mechanism to the drive state.
4. A winder according to claim 3 , wherein the other of the drive member and the cam member further comprises a free cam surface to engage the boss upon rotation of the drive member in the free direction, to move the transmission mechanism to the free state.
5. A winder according to claim 3 , wherein the boss is on the drive member.
6. A winder according to claim 5 , wherein the boss is on an inner surface of the drive member.
7. A winder according to claim 1 , further comprising a biasing element to bias the intermediate transmission member and the driven member apart and create a second disengagement point between the intermediate transmission member and the driven member when the transmission mechanism is in the free state.
8. A winder according to claim 7 , wherein the biasing element is a compression spring.
9. A winder according to claim 1 , wherein the intermediate resistor comprises a helical spring.
10. A winder according to claim 1 , wherein the drive member comprises a chain wheel.
11. A blind system comprising:
a first blind;
a second blind;
a first winder in accordance with claim 1 , to operate the first blind;
a second winder in accordance with claim 1 , to operate the second blind,
wherein rotation of the drive member of the first winder in the drive direction causes the drive member of the second winder to rotate in the free direction, and rotation of the drive member of the second winder in the drive direction causes the drive member of the first winder to rotate in the free direction.
12. A blind system according to claim 11 , wherein the blind system further comprises a cord engaged with the drive member of the first winder and the drive member of the second winder, wherein rotation of the drive member of the first winder in the drive direction is achieved by moving the cord in one direction, and rotation of the drive member of the second winder in the drive direction is achieved by moving the cord in the other direction.
13. A blind system according to claim 11 , further comprising a first position stop to hold the first blind in position, when the cord is not operated.
14. A blind system according to claim 13 , further comprising a first spring booster to retract the first blind, when the first position stop is released.
15. A blind system according to claim 13 , further comprising a second position stop to hold the second blind in position, when the cord is not operated.
16. A blind system according to claim 15 , further comprising a second spring booster to retract the second blind, when the second position stop is released.
17. A winder for a blind system, comprising:
a drive member rotatable in a drive direction and a free direction;
a driven member to engage a blind cylinder;
a transmission mechanism to selectively transmit rotation of the drive member to the driven member, the transmission mechanism including a cam member, an intermediate transmission member and an intermediate resistor to provide resistance to rotation of the intermediate transmission member,
wherein the transmission mechanism has:
a drive state when the drive member is rotated in the drive direction to overcome the resistance of the intermediate resistor and transmit rotation of the drive member through the intermediate transmission to the driven member, and
a free state when the drive member is rotated in the free direction, wherein transmission is broken between the drive member and the intermediate transmission member and between the drive member and the intermediate resistor;
wherein there is no clutch resistance to rotation of the drive member in the free direction when the transmission mechanism is in the free state.
18. A winder according to claim 17 , wherein the cam member selectively creates a first disengagement point between the drive member and the intermediate transmission member when the drive member is rotated in the free direction, and closes the first disengagement point when the drive member is rotated in the drive direction.
19. A winder according to claim 18 , wherein one of the drive member and the cam member comprises a boss, and the other of the drive member and the cam member comprises a drive cam surface to engage the boss upon rotation of the drive member in the drive direction, to move the transmission mechanism to the drive state.
20. A winder according to claim 19 , wherein the other of the drive member and the cam member further comprises a free cam surface to engage the boss upon rotation of the drive member in the free direction, to move the transmission mechanism to the free state.
21. A winder according to claim 19 , wherein the boss is on the drive member.
22. A winder according to claim 21 , wherein the boss is on an inner surface of the drive member.
23. A winder according to claim 17 , further comprising a biasing element to bias the intermediate transmission member and the driven member apart and create a second disengagement point between the intermediate transmission member and the driven member when the transmission mechanism is in the free state.
24. A winder according to claim 23 , wherein the biasing element is a compression spring.
25. A winder according to claim 17 , wherein the intermediate resistor comprises a helical spring.
26. A winder according to claim 17 , wherein the drive member comprises a chain wheel.